D.P.
I flew with my 2-year-old in a carseat once (the first time I flew alone with him) and it counted as twice: first and last time. It was a giant hassle. We've flown from Seattle to central California, and also Seattle to Chicago to Iowa (and worse: Seattle to Dallas to Iowa) since he was an infant and have never felt we needed the carseat. Kiddo sits by the window (or between us) and it's been fine.